臨床治療牙齒缺損有三種方式，分別為固定假牙、活動假牙與人工植牙。人工植牙不論在咬合功能、整體美學、使用壽命與牙齦狀況等均優於其他治療方式。即便如此，人工牙根發展至今已超過四十年以上的歷史，臨床上仍有超過一成以上之失敗率，其因素包括骨質狀況、手術優劣、植入區域、細菌感染、牙根零件機械失效與牙根在齒槽骨的穩定度…等。牙根零件機械失效原因包含連接桿斷裂、人工牙根螺牙斷裂、牙墩破裂以及人工牙根與牙墩卡榫機制的破壞等，而其中人工牙根與牙墩的卡榫機構對整體牙根與牙墩的強度影響很大，卡榫機構主要目的為抗扭，但在設計上不但可以保護連接桿亦可以增強牙墩的強度。 本研究利用Solidworks針對人工牙根與牙墩的卡榫機構做一系列的設計並建立九組不用的模型並做有限元素分析，包含內外六角形與梅花形卡榫比較、卡榫高度分析、管狀插銷高度分析與錐度平台的分析，分析結果顯示人工牙根卡榫機構以有管狀插銷且有錐狀平台的為較佳，卡榫高度與管狀插銷高度都是較高的較佳，因此本研究的人工牙根與牙墩卡榫設計，採用高度為1 mm的內梅花型卡榫，並包含長度為3 mm的管狀插銷與錐狀平台為最佳設計，以降低發生牙根零件失效的機率。 There are three ways to treat damages of tooth in clinical trial include dentures that movable ,dentures that fixed and dental implant. No matter in occlusion , aesthetics or life time ,dental implant is a better treatment than the others .Even though ,dental implant have developed more than 40 years, the failing rate was still more than 10 percent in clinic. The reason are bone mineral density (BMD),the pros and cons of surgery ,the area of surgery , bacterial infection and the mechanical failing of dental implant. The reason cause mechanical failing of dental implant are fracture of linkage, screw of implant ,abutment and the tenon of implant and abutment. And the major effect is the tenon of implant and abutment. The tenon of implant and abutment is not only to against torsion but also protect linkage and abutment. The study designs and builds and analyzes nine models of dental implant and abutment by Solidworks. There are external and internal of hex, torx, height of tenon, height of tube and tape. The result show that a dental implant has tube and tape is better and the height of the tenon and tube are the longer one is the best. Therefore, the study used the torx shaped tenon which height is 1 mm and the best design included 3 mm height tube and tape in order to reduce the risk of mechanical failing.
